Heavy rain fell across Philadelphia and caused widespread poor drainage flooding on the 2nd and stream and river flooding on the 2nd and 3rd. Rain started late in the evening on the 1st and continued throughout the day on the 2nd. The rain fell at its heaviest during the afternoon of the 2nd. The rain tapered off to some spottier light rain or drizzle during the evening and overnight and ended during the morning on the 3rd. Storm totals averaged around 3 inches with higher amounts over the source region of some of the streams in Montgomery County. The heavy rain and flooding caused the closure of Kelly Drive and Lincoln Drive along the Schuylkill River and Delaware Avenue along the Delaware River. The Schuylkill River within Philadelphia was above its 11 foot flood stage from 9 p.m. EST on the 2nd through 1239 p.m. EDT on the 3rd. It crested at 11.74 feet at 430 a.m. EDT on the 3rd. The Pennypack Creek at the Rhawn Street Bridge was above its 7 foot flood stage from 538 p.m. EST on the 2nd through 408 a.m. EDT on the 3rd. It crested at 9.74 feet at 1245 a.m. EST on the 3rd. The Wissahickon Creek at its mouth with the Schuylkill River was above its 5 foot flood stage from 422 p.m. EST on the 2nd through 654 a.m. EDT on the 3rd. It crested at 7.81 feet at 145 a.m. EST on the 3rd. The Frankford Creek at Castor Avenue was above its 7 foot flood stage from 510 p.m through 612 p.m. EST on the 2nd. It crested at 7.4 feet at 545 p.m. EST.  The Delaware River at Pier 11 in Philadelphia caused moderate tidal flooding at the time of the evening high tide on the 2nd. The high tide reached 9.59 feet above mean lower low water at 754 p.m. EST on the 2nd and was above minor tidal flooding levels (8.2 feet above mean lower low water) from 544 p.m. EST through 1002 p.m. EST on the 2nd. Some additional minor tidal flooding occurred during the morning high tide cycle the next three mornings. Specific storm totals included 2.85 inches at the Philadelphia International Airport and 2.74 inches at the Northeast Philadelphia Airport.  The flooding heavy rain was caused by a low pressure system that moved from the southern Gulf Coast States on the morning of April 1st northeast to the eastern Tennessee Valley during the evening of the 1st, to far western Virginia just after Midnight EST on the 2nd, into central Virginia at 7 a.m. EST on the 2nd, near Washington, D.C. at 1 p.m. EST on the 2nd, near Lancaster, Pennsylvania at 7 p.m. EST on the 2nd, near Scranton, Pennsylvania at 1 a.m. EST on the 3rd, over the Finger Lakes in New York at 8 a.m. EDT on the 3rd and into eastern Lake Ontario at 2 p.m. EDT on the 3rd. The strong southeast flow preceding the low pressure system was able to entrain Atlantic Ocean moisture in addition to the Gulf of Mexico moisture into the system. The southeast flow also was ideal for orographic lifting in the Poconos and other higher terrain. The flooding was exacerbated by the already wet soil conditions due to heavy rain on both March 23rd and 28th. In addition, along the Delaware River, snowmelt in the upper basin in New York State and because the New York City Delaware County, New York reservoirs were already at capacity added to the flooding.

Flood in PHILADELPHIA, PENNSYLVANIA
From 02-APR-05 16:22:00 to 03-APR-05 05:54:00 (EST)
Reported by: AWOS,ASOS,MESONET,ETC